Disclaimer: I work at Backblaze so you should check up to see if what I say is true and keep me honest.

> Zero-knowledge encryption? You don’t need that[0][1].

This is not our position, and I feel it is disingenuous of you to say that. If you read YOUR TOP LINK from TWO YEARS AGO I explain that Backblaze specifically offers 4 levels of security, one of which is Zero Knowledge, and we think that is a perfectly valid decision for some customers. If you want zero knowledge, choose it at Backblaze! But some customers have other requirements, and you are insisting that we remove part of our product line up that is very useful to other people.

Here are the four levels of security Backblaze offers, most of this is from this post 18 days ago I wrote: https://www.reddit.com/r/backblaze/comments/kroqhn/private_e...

1) Security Level 1 - no security. Backblaze B2 can serve public websites, on purpose, the way stuff that you want to go viral and share with everybody. https://www.ski-epic.com is supposed to be readable, not locked. These are totally open files for anybody to download.

Security Level 2 - username/password/2-factor. This is a good choice for the customers who would rather error on the side of recovering their passwords than losing all their backups. In this level of security, your Online Backup is secured by your username and password, and every file is "encrypted at rest" (all the files are always encrypted when stored on disk). In this mode, all it takes to decrypt your backup is to sign into the Backblaze website with your username and password, and 2-factor verification, and you can prepare a ZIP file restore to download. You can ALSO prepare an encrypted USB restore hard drive to be sent to your home. This particular level of security has the advantage (or disadvantage to the security sensitive) that if you forget your password, you can "recover" it through your email account. If you use 2-factor (like we recommend), a hacker with your username and password will STILL not be able to gain access to your files. This is a good choice for a customer who is not super overly concerned about hackers possibly getting their data, and just wants to backup a public website like https://www.ski-epic.com (which anybody could get from the website anyway), or some photos of their wedding. It errors on the side of being able to recover the data no matter what. Some things you want BACK more than you want to destroy the files in the event of a hacker breach, or if you forget your password.

Security Level 3 - Backblaze Personal Backup with a "custom" unrecoverable private encryption key. In this mode, your account is protected with your username, password, 2-factor like the above "security level 2", but also an ADDITIONAL "unrecoverable" passphrase that Backblaze does not know in any way, shape, or form for years. Without the passphrase your files cannot be decrypted. You only provide the "passphrase' in the event of preparing a restore, and then your passphrase is never stored on disk anywhere at Backblaze, it is held in RAM. For years your files are encrypted at rest where even if Backblaze is ordered by government subpoena to hand over your files Backblaze cannot comply even if we wanted to, we have no way to decrypt your files. If you choose this level of security, DO NOT FORGET that passphrase because there is no possible way to "recover" it, and without it your files are GONE. You cannot recover them, Backblaze cannot recover them, the CIA or FBI cannot recover them - they are GONE. Now, as long as you don't forget that passphrase, then years later when you actually need to prepare a restore, there is a security "window of exposure" for as little as 20 minutes ONLY IF (and when) you go to restore. If you are under arrest -> just don't prepare a restore, and the FBI simply cannot get the contents of your files. An alternative strategy is if you have some particularly sensitive files, like incriminating evidence of your crimes or your tax returns or a file with all of your passwords to your bank accounts, put these few files in a small encrypted file on your laptop, and EVEN IF you prepare a restore the FBI (or Backblaze, or hackers) cannot get the contents of those files. Now, the reason we allow the customer to provide this passphrase is it is STILL relatively friendly, and we can prepare 8 TByte USB restore drive (that is encrypted) and sent to the customer's home. While there is that tiny exposure if the restore servers were ACTIVELY hacked during the 20 minutes while the restore is being prepared, some customers (especially if they are just storing wedding photos and cat pictures and public websites) prefer this option. Many of our customers are naive (not computer expert) customers, and many, many, many customers find this particular security level, convenience, and tradeoff useful.

Security Level 4 - "Zero Knowledge". Customers can use Backblaze B2 with a zero knowledge product such as some of the products listed on this web page: https://www.backblaze.com/b2/integrations.html Some of those 3rd party tools are even open source if a customer doesn't trust commercial products and wants to read the source code. This is a very useful security level for customers that would rather LOSE THE DATA than ever have it intercepted by law enforcement or a hacker. Backblaze offers this level if you want it! However, there are some very real world drawbacks of this level of security. First of all, Backblaze cannot prepare an 8 TByte hard drive with all your files organized correctly as they were backed up and send it to you fully organized, because "zero knowledge" demands Backblaze never, under any circumstances, know any of your file names. This is a more secure system, but it is less convenient to restore. Also, some of our customers don't have the bandwidth to download 8 TBytes conveniently, so you may have to pay more money for a faster internet connection to make this type of backup work for you. The other thing that is "dangerous" or less convenient and might lead to data loss in this scenario is that if a customer stores the "Private Key" on the laptop that is being backed up, and the laptop SSD dies, they actually lose the backup also, because you need the keys to decrypt the backup. So any customer who chooses this security level needs to make several copies of their "Private Key" they never give Backblaze, probably on multiple different external hard drives in their home (in case one of those copies of the key "goes bad" you need multiple copies). Beware of a house fire that destroys the laptop, and all the extra copies of the security keys, because this will result in loss of the backup also! So one idea is to store the keys in a DIFFERENT online service (or two or three online services) elsewhere on the internet (not at Backblaze, because that is what is demanded by "zero knowledge"). Again, this is a great choice for customers that PREFER DATA LOSS and extra time and thought and effort and cost over allowing the FBI or a hacker to gain access to their files. This is a perfectly valid choice, and Backblaze offers it.

Now sometimes people accuse Backblaze of not being a "zero knowledge" backup. What they are saying is that only #4 is "valid" and they really want Backblaze to stop offering #1, #2, or #3. I reject their insistence that we not offer easy backups for cat pictures and that customers must all share their technical ability (and bandwidth, and time) to download the encrypted data instead of getting a USB restore hard drive prepared with all their files in a friendly fashion sent to them. Some customers have different use cases, and Backblaze strives to support all four of these use cases! Pick which is right for you!